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f(x)={[2^(x)," for "0 < x <= 4],[8sqrtx," for "x > 4]:}
Find 
lim_(x rarr4)f(x).
Choose 1 answer:
(A) 4
(B) 8
(C) 16
(D) The limit doesn't exist.

f(x)={2xamp; for 0<x4=""8=""=""=""x=""=""=""=""for=""=""x="">4 f(x)=\left\{\begin{array}{ll} 2^{x} &amp; \text { for } 0<x 4="" 8="" \leq="" \\="" \sqrt{x}="" &="" \text="" {="" for="" }="" x="">4 \end{array}\right. \newlineFind limx4f(x) \lim _{x \rightarrow 4} f(x) .\newlineChoose 11 answer:\newline(A) 44\newline(B) 88\newline(C) 1616\newline(D) The limit doesn't exist.

Full solution

Q. f(x)={2x for 0<x48x for x>4 f(x)=\left\{\begin{array}{ll} 2^{x} & \text { for } 0<x \leq 4 \\ 8 \sqrt{x} & \text { for } x>4 \end{array}\right. \newlineFind limx4f(x) \lim _{x \rightarrow 4} f(x) .\newlineChoose 11 answer:\newline(A) 44\newline(B) 88\newline(C) 1616\newline(D) The limit doesn't exist.
  1. Find the limit of f(x)f(x) as xx approaches 44: We need to find the limit of the function f(x)f(x) as xx approaches 44. The function is defined differently for two intervals: when 0 < x \leq 4, f(x)=2xf(x) = 2^x, and when x > 4, f(x)=8xf(x) = 8\sqrt{x}. To find the limit as xx approaches 44, we need to consider the value of the function as xx gets closer to 44 from both sides.
  2. Calculate the limit from the left side: First, let's consider the limit from the left side as xx approaches 44. For xx in the interval (0,4](0, 4], the function is defined as f(x)=2xf(x) = 2^x. So we need to calculate the limit of 2x2^x as xx approaches 44 from the left.
  3. Calculate the value of 242^4: Calculating the limit from the left, we have:\newlinelimx42x=24\lim_{x \to 4^-} 2^x = 2^4\newlineThis is because the function 2x2^x is continuous, and we can simply substitute the value of xx with 44.
  4. Calculate the limit from the right side: Now, let's calculate the value of 242^4: \newline24=2×2×2×2=162^4 = 2 \times 2 \times 2 \times 2 = 16\newlineSo, the limit from the left as xx approaches 44 is 1616.
  5. Consider the values of f(x)f(x) as xx approaches 44: Next, we need to consider the limit from the right side as xx approaches 44. For xx in the interval (4,)(4, \infty), the function is defined as f(x)=8xf(x) = 8\sqrt{x}. However, since we are only interested in the limit as xx approaches 44, we do not need to evaluate this expression because it is not defined at xx00.
  6. Check if the limits from the left and the right are equal: Since the function f(x)f(x) is not defined for xx exactly equal to 44, we only consider the values of f(x)f(x) as xx approaches 44 from the left and the right. We have already found that the limit from the left is 1616. The limit from the right does not exist because the function changes at x=4x = 4.
  7. Conclusion: The limit of f(x)f(x) as xx approaches 44 is 1616: To determine if the overall limit exists, we need to check if the limits from the left and the right are equal. Since the function changes at x=4x = 4 and we only have the limit from the left, we conclude that the limit of f(x)f(x) as xx approaches 44 is 1616.

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